Combined air filter and silencer



March 27, 1945. 3` G VOKES COMBINED AIR FILTER AND SILENCEH Filed Jan.5, 1944 2 Sheets-Sheet l Patented Mar. 27, V194s UNITI-:p STATES PATENTori-ics Cecil Gordon Vokes, London, England Application January 3, 1944,Serial No. 516,814 In Great Britain December 28, 1942 s claims. (ci.18a- 44) This invention relates to combined filters and silencers, moreespecially designed for air intake of internal combustion engines orcompressors. It lends itself to a particularly neat and effective filterand silencer for multi-cylinder Diesel and like engines in which outsideair is drawn into the cylinders.

In arrangements according to the invention (as applied to air intakes)the air is drawn in through passages formed in substantial thicknessesof sound-absorbing material and filled with easily removable andreplaceable filtering material into a space of which the walls are ofsound deadening or absorbing nature and from which the outlet leads. Inpreferred forms, the passages are formed in two opposite walls, 'whichmay be parallel, and the outlet is, broadly speaking, perpendicular tothe flow of the air into the space from which it leads. In some cases itmay be convenient to carry the plugs or lengths of filtering materialdisposed in passages in two opposite walls on a common stem or to mounta number of them or of such stems on av common backing or` finger grip,so that theycan be simultaneously withdrawn and replaced. The materialcan be of the nature of tufts of wire or bristle or the like radiatingfrom a stem: or a coil or roll of suitable woven or spun or crinkled ortwisted me..

tallic or textile or animal filaments or asbestos or mixed materialslike decorative tinsel; or a foraminated container filled with suchmaterials vor any other appropriate material according to the nature anddegree of filtration and silence required, the idea being to usesomething of the nature of a plug of looser more permeable material ineach passage through the felt or other sound absorbing thickness..

Other parts of the invention are embodied in the typical form shown bythe accompanying same with the filter-silencer portion in section.

An elongated casing i oi' rectangular crosssection has an elongatedopening 2 along one side designed to fit over the air intakes to anumber of ln-line cylinders 3 of a Diesel engine. The top and'bottomwalls are both lined with a number of layers 4 of felt retained by aninner wall 5 and a number of holes are formed right through these wallsand the felt filling. The side and end walls can be lined with felt asindicated at 6. The filtering plugs 1 can be mounted in pairs on acommon stem 8 so that all can be inserted from the top, where simpleretaining rods 9 may be used to keep them in position. In other forms aswill -be obvious without illustration, the holes in the opposite wallscan be staggered or there could` be holes and plugs in one flat wallonly. It will be understood that the only access to the casing when theapparatus is assembled and fitted* is through the filtering plugs,

I claim:

1. A combined filter and silencer having a casing with substantiallyflat walls and formed with an outlet. sound labsorbing material liningthe walls in substantial thickness, said material being formed with aplurality of passages extending therethrough with the passages alinedthrough the material on opposite sides of the casing, readilyreplaceable plugs of filtering material filling the said passages, andcommon stems carrying the plugs in the alined passages.

2. A combined filter and silencer including a casing havingsubstantially fiat walls and formed with an outlet. multiple thicknessesof sounding material lining the said walls. said material being formedwith a plurality of passages extending therethrough and alined withopenings in the walls, and plugs of filtering material filling saidpassages in the material and readily removable and replaceable throughthe openings in the said walls, the said walls being alined at oppositesides of the casing and the` outlet being arranged trans. verse to saidwalls.

y 3. A combined filter and silencer as described in claim 2 wherein theoutlet is elongated to simultaneously cooperate with a number ofcylinder intakes.

" CECIL GORDON VOKEB.

